Some VM (5 have the problem) can't ping other VM on another host: So VM1 on host1 can't ping VM2 and VM3 on host2 BUT can ping VM4 on host2!! By this time, VM1 can ping all other VM on host1 and all other on host3. This behaviour is "unpredictable". Sometimes it's a VM from host3 who have problem with VM on host1..

I solve the problem by different way: assigning static MAC adress, deleting network card on VM and create new one, create legacy acrd instead of network card, deleting all entry in the registry from old card, etc.

Now I have two VM where I already try all thoses solutions without succes!

It's not a VLAN problem as when a VM can't ping another one, it can ping some other in the same VLAN and across others VLAN...

Here's another test i've made: If i take VM1 who's in problem (VM1 on Host1 can't ping VM2 on Host2) and VM3 who's OK. I shut those two VMs, and switch the MAC adresse and IP between the VMS, VM1 start to work OK and VM3 is in problem. So i think it's a MAC problem! But if i try to put different static MAC to all my VM i still have the problem.

Another information: all my physical host are SUN Fire x4170 with 4 Intel Network cards. The first NIC is reserved for manageemnt and the other tree are in Teaming (command line :PROSetCL.exe Team_Create 1,3,4 TeamVM VMLB)for Virtual Machine Load Balancing. No special configuration on the Cisco switch.

Hopefully we'll be able to apply these today, I'll let you know if it works for us. VMLB sounds cool so we went with it, it seems to be more dynamic then the other teaming options. Note that since none of this has worked properly yet I can't say if its cool or not!